In some integrated circuits, alternate interconnect paths are created to increase yield. For example, in SRAM circuits, after the last interconnect level is formed, the functionality of the device is measured. Defective interconnect paths are severed and replaced with alternative interconnect paths. The defective interconnect paths are severed by "blowing" a fuse. FIGS. 1A and 1B show a fuse 30 before and after the fuse 30 is blown, respectively. During this process, a high power laser is used to "blow" a portion of the capping layer 16 overlying the metal 20. The capping layer typically comprises silicon nitride or oxide. During this process, the metal 20 of the fuse 30 can reach an extremely high temperature (e.g., 2000.degree. C.). As a result, the metal 20 of the fuse 30 is blown out of the fuse area within interconnect level 14. Unfortunately, some of the material from the fuse 30 is redeposited on the sidewalls of the fuse 30 and on the surface of the device. This material is referred to a slag 22. Slag 22 comprises both the metal 20 of the fuse and the liner material 18 of the fuse. To avoid unwanted shorts, the slag 22 must be removed.
Etch sequences to remove aluminum (Al) slag and TiN liners are known in the art. However, copper metal interconnects are being developed to replace aluminum interconnects to improve performance. Accordingly, there is a need to replace the Al-slag and TiN liner etch sequence with a Cu-slag and appropriate liner etch sequence.